User will give source and destination zip codes in csv file my application will give results using osrm-backend. But OSRM accepts only lat and long as input, so I need to convert zip code to lat long ...

When I try to convert the data type for that column, the zip+4 values are fine, but the zip codes end up looking like 00001-9426 (for zip code 19426), causing them to not sort properly, etc.